The present invention relates to a golf ball which has a flight distance that can be reduced compared with official golf balls currently in use, yet has the same good feel on impact and excellent controllability and durability as a game ball, thus making it suitable for use not only as a game ball, but also as a practice range ball.
Recently, in the following two cases, there has been an increased desire for reduced-flight golf balls.
The first case has to do with the fact that, at “driving range” type golf ball practice ranges, because the practice ranges cannot be made sufficiently large in size, balls hit by golfers end up flying out of the range. Reduced-flight golf balls are desired in order to resolve this problem.
The second case concerns golf courses where the distance from the teeing ground to the green is short. On such courses, to enjoy the game using distance clubs such as drivers, there is a desire on the part of golfers to limit the distance traveled by the ball.
Of the golf balls that have been disclosed to date, a few are golf balls which intentionally restrict the flight performance or are designed to travel a short distance. For example, JP-A 60-194967 describes a short distance golf ball which includes a foam-molded thermoplastic resin polymer and filler material, and has a density gradient that increases along the radius thereof from the center to the surface of the ball.
However, this golf ball undergoes an excessive loss of distance not only at high head speeds, but also at low head speeds, making it too disadvantageous to the golfer in competition.
U.S. Pat. No. 5,209,485 teaches a golf ball which has a low rebound and a reduced distance. However, this ball has a high hardness and thus an unpleasant feel on impact.
U.S. Pat. No. 5,273,287 discloses a large-diameter golf ball having a diameter of from 1.70 to 1.80 inches (43.18 to 45.72 mm), a weight of not more than 1.62 ounces, and a dimple surface coverage of at least 70% relative to the spherical surface of the ball. Yet, because the ball is larger than normal, it feels strange to the player. Moreover, the feel on impact has not been improved.
U.S. Pat. No. 5,971,870 and U.S. Pat. No. 5,695,413 describe golf balls having a soft core. However, because the purpose of these inventions is to provide a good flight performance, they differ from the present invention in their fundamental aims.
JP-A 2007-301357 discloses golf balls for which properties such as the initial velocity, amount of deformation and cover hardness are specified. However, such golf balls do not exhibit a sufficient reduction in distance, in addition to which they have a large deflection at the time of impact and thus too soft a feel. Also, JP-A 2-295573 and JP-A 4-117969 disclose golf balls which are intended to have a low flight trajectory, but these balls lack excellence with respect to all of the following: feel, controllability and durability.